2005 INFINITI QX4 battery

BL-100
AUTOMATIC BACK DOOR SYSTEM
Revision: October 20052005 QX56
System DescriptionEIS0 08 R4
NOTE:
The automatic back door system must be initialized by fully closing the back door anytime the battery
or the back door control unit has been disconnected.
The automatic back door system consists of a one piece unit that combines the back door control unit along
with the back door motor, back door clutch and the back door encoder. The back door latch contains a lock
function that can control the two functions of automatic back door latch closure and electrical opener with a
single motor when you close the back door to the halfway-state.

Back door auto closure
When the back door is closed to the halfway state (half-latch) position, the motor automatically drives to
rotate the latch lever and pull it in from half latched to full latched.

Power back door
With the back door closed, press the power liftgate switch or press the remote keyless entry button, or pull
the back door handle with the back door unlocked, the back door latch motor opens the locking plate and
releases the latch. The back door motor then raises the door to the full open position.
With the back door fully open, press the power liftgate switch, remote keyless entry button or the back
door close switch, the back door motor closes the door to the half-latch state. The back door latch motor
then drives the latch to the full close position.
At the onset of each power open or power close application, the hazard lamps will flash 3 times and the
warning chime will sound 3 times lasting a total of 2 seconds.
OPERATION DESCRIPTION
Power Liftgate Switch Operation (Fully Closed → Fully Open Operation)

When the power liftgate switch is pressed, back door control unit terminal 23 receives the signal.

The back door control unit checks the A/T selector lever (P position) through terminal 18, vehicle speed
through terminal 21, ignition status through terminal 7, glass hatch is closed through terminal 17 and bat-
tery voltage is present through terminal 3.

When the back door control unit receives the signal, if the auto back door operating enable conditions are
met, it sends a 5 volt signal through terminal 6 and grounds terminal 9 to sound the warning chime, sends
a signal to the BCM through terminal 4 to flash the hazard lamps and unlocks the back door latch through
terminal 12.

The back door control unit supplies power to the magnetic clutch and the back door motor and moves the
back door in the open direction. (At this time, it also executes speed control, input reverse, and anti-pinch
detection control.)

When the back door is opened to the full-open position, the full-open position is detected by the encoder,
and the back door control unit switches the back door motor OFF and the magnetic clutch is pulsed and
then turned OFF.

The back door is held in the fully open position by the gas stays.
Remote Keyless Entry Operation (Fully Closed → Fully Open Operation)

When the remote keyless entry button is pressed for at least 0.5 seconds, back door control unit terminal
21 receives the signal.

The back door control unit checks the A/T selector lever (P position) through terminal 18, vehicle speed
through terminal 21, ignition status through terminal 7, glass hatch is closed through terminal 17 and bat-
tery voltage is present through terminal 3.

When the back door control unit receives the signal, if the auto back door operating enable conditions are
met, it sends a 5 volt signal through terminal 6 and grounds terminal 9 to sound the warning chime, sends
a signal to the BCM through terminal 4 to flash the hazard lamps and unlocks the back door latch through
terminal 12.

The back door control unit supplies power to the magnetic clutch and the back door motor and moves the
back door in the open direction. (At this time, it also executes speed control, input reverse, and anti-pinch
detection control.)

When the back door is opened to the full-open position, the full-open position is detected by the encoder,
and the back door control unit switches the back door motor OFF and the magnetic clutch is pulsed and
then turned OFF.

The back door is held in the fully open position by the gas stays.

AUTOMATIC BACK DOOR SYSTEM
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Revision: October 20052005 QX56
Back Door Handle Switch Operation (Fully Closed → Fully Open Operation)

When the back door handle is pulled, back door control unit terminal 26 receives the signal.

The back door control unit checks that the back door is unlocked and checks the A/T selector lever (P
position) through terminal 18, vehicle speed through terminal 21, ignition status through terminal 7, glass
hatch is closed, battery voltage and back door close switch position through terminal 13.

When the back door control unit receives the signal, if all auto back door operating enable conditions are
met, it sends a 5 volt signal through terminal 6 and grounds terminal 9 to sound the warning chime, sends
a signal to the BCM through terminal 4 to flash the hazard lamps and unlocks the back door latch through
terminal 12.

The back door control unit supplies power to the magnetic clutch and the back door motor and moves the
back door in the open direction. (At this time, it also executes speed control, input reverse, and anti-pinch
detection control.)

When the back door is opened to the full-open position, the full-open position is detected by the encoder,
and the back door control unit switches the back door motor OFF and the magnetic clutch is pulsed and
then turned OFF.

The back door is held in the fully open position by the gas stays.
Power Liftgate Switch Operation (Fully Open → Fully Closed Operation)

When the power liftgate switch is pressed, the back door control unit terminal 23 receives the signal.

The back door control units checks door position through the rotary encoder.

When the back door control unit receives the signal, if the auto back door operating enable conditions are
met, it sends a signal through terminal 6 and grounds terminal 9 to sound the warning chime and sends a
signal to the BCM through terminal 4 to flash the hazard lamps.

The back door control unit supplies power to the magnetic clutch and the back door motor and move the
back door in the close direction. (At this time, it also executes speed control, input reverse, and anti-pinch
detection control.)

When the back door reaches the half-latch state, the half-latch switch detects this and the signal is sent to
the back door control unit terminal 22.

When the back door control unit receives the half latch switch signal, it switches OFF the back door motor
and the magnetic clutch and operates the cinch latch motor.

When the back door latch operates and full close is detected through terminal 14 of the back door control
unit, the cinch latch motor reverses to the neutral position and the back door auto closure operation ends
and the door is fully closed.
Remote Keyless Entry Operation (Fully Open → Fully Closed Operation)

When the remote keyless entry switch is pressed for at least 0.5 seconds, the back door control unit termi-
nal 21 receives the signal.

The back door control units checks door position through the rotary encoder.

When the back door control unit receives the signal, if the auto back door operating enable conditions are
met, it sends a signal through terminal 6 and grounds terminal 9 to sound the warning chime and sends a
signal to the BCM through terminal 4 to flash the hazard lamps.

The back door control unit supplies power to the magnetic clutch and the back door motor and move the
back door in the close direction. (At this time, it also executes speed control, input reverse, and anti-pinch
detection control.)

When the back door reaches the half-latch state, the half-latch switch detects this and the signal is sent to
the back door control unit terminal 22.

When the back door control unit receives the half latch switch signal, it switches OFF the back door motor
and the magnetic clutch and operates the cinch latch motor.

When the back door latch operates and full close is detected through terminal 14 of the back door control
unit, the cinch latch motor reverses to the neutral position and the back door auto closure operation ends
and the door is fully closed.

BL-102
AUTOMATIC BACK DOOR SYSTEM
Revision: October 20052005 QX56
Back Door Close Switch Operation (Fully Open → Fully Closed Operation)

When the back door close switch is pressed, the back door control unit terminal 8 receives the signal.

The back door control units checks back door close switch terminal 13 status and door position (must be
fully opened), through rotary encoder and battery voltage.

When the back door control unit receives the signal, if the auto back door operating enable conditions are
met, it sends a signal through terminal 6 and grounds terminal 9 to sound the warning chime and sends a
signal to the BCM through terminal 4 to flash the hazard lamps.

The back door control unit supplies power to the magnetic clutch and the back door motor and move the
back door in the close direction. (At this time, it also executes speed control, input reverse, and anti-pinch
detection control.)

When the back door reaches the half-latch state, the half-latch switch detects this and the signal is sent to
the back door control unit terminal 22.

When the back door control unit receives the half latch switch signal, it switches OFF the back door motor
and the magnetic clutch and operates the cinch latch motor.

When the back door latch operates and full close is detected through terminal 14 of the back door control
unit, the cinch latch motor reverses to the neutral position and the back door auto closure operation ends
and the door is fully closed.
Reversal

If the power liftgate switch, remote keyless entry switch or the back door close switch is pressed during
back door power open and close operation, the back door will reverse direction.

If the outside handle switch is pulled during power open or power close, the power back door will automat-
ically stop and go to manual mode.
Anti-Pinch Function

During auto open or close operation, if an object is detected in the door's path, the back door operates in
the reverse direction until fully closed or open to prevent pinching.

During auto close operation, if an object is detected by the pinch strips in the door's path, the back door
operates in the open direction until it is fully open.

During auto cinch latch operation, if an object is detected by the pinch strips in the door's path, the back
door operates depending on the back door close switch position. If the back door close switch is in the
OFF position, the back door operates in the open direction until it is fully open. If the back door close
switch is in the ON position, the back door will reverse only until the latch is fully released.

If the pinch strips are present but are not functioning properly (permanently sensing a pinch), the auto-
matic back door system will operate in the open direction only.

If the pinch strips are not connected to the automatic back door system, it will not operate.
Gas Stay Check

During each power open operation, the back door control unit monitors motor current draw to determine if
the gas stays are functioning properly.

If a failure of the gas stays is detected, the back door control unit will close the back door while sounding
the warning chime.
Warning Functions

The warning chime is sounded according to the back door operating state, operations, and conditions.

AUTOMATIC BACK DOOR SYSTEM
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Revision: October 20052005 QX56
Auto Back Door Operation Enable Conditions
Control When Operating Enable Conditions Not Met During Power Open/Close
Control When Operating Enable Conditions No Longer Met
Operation Power liftgate switch Remote keyless entry Back door handle switchBack door
close switch
Operating
directionFully closed →
openFully open →
closedFully closed →
openFully open
→ closedFully closed →
openFully open →
closedFully open →
closed
Close
switchCANCEL or NEUTRAL NEUTRAL NEUTRAL
Vehicle stop
conditionA/T selector
lever in P or N
range and vehi-
cle speed less
than 2 km/h or
ignition switch
in OFF position—A/T selector
lever in P or N
range and vehi-
cle speed less
than 2 km/h or
ignition switch
in OFF position—A/T selector
lever in P or N
range and vehi-
cle speed less
than 2 km/h or
ignition switch
in OFF position——
Battery volt-
ageApprox. 11V or more
Back door
lock status— — — — Unlocked — —
Glass hatch Closed
Items Operation condition Not met case Control
A/T selector lever P positionP or N position with ignition ON
or any position with ignition
OFFOtherContinue power open or close,
but sounds warning chime.
Back door close switch NEUTRAL CANCEL
Cancels power open/close
operation or door will release to
manual mode. Voltage drop 11V or more11 > V > 9
9 > V > reset voltage
reset voltage > V No power function available
Handle switch Normal (GND) Error (OPEN)No operation. Cancel power
open/close release to manual.
Glass hatch Closed OFFCancels power door open oper-
ation, door will release to man-
ual mode.
Description Operation Control
Back door close switch turned to CANCELWarning chime active
→ Shift to manual mode after full open or
close operation is complete
(Recovery to power mode when main
switch turned OFF or door fully closed)→ Shift to manual mode
A/T selector lever P or N position with igni-
tion switch ONWarning chime active and one-way opera-
tion continuous
(Warning chime inactive and door fully
open or fully closed or operating conditions
recovered)Full open: power close operation allowed
Full close: operating conditions not met →
no power open function.
Voltage drop 11 - 9VOne-way operation continued (equivalent
to the case of starting voltage ← 11V for
handle operation with warning chime
active)Not allowed
Voltage drop less than 9V
(Microcomputer reset voltage - clutch hold
voltage)

Motor stopped

Clutch may slip

Control not possible because microcom-
puter being resetControl not possible because microcom-
puter being reset

AUTOMATIC BACK DOOR SYSTEM
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Revision: October 20052005 QX56
Terminals and Reference Value for Back Door Control UnitEIS008R7
Te r m i n a l Wire
ColorItem ConditionVoltage (V)
(Approx.)
1 B Ground — —
2 B Ground — —
3 Y/R Battery power supply — Battery voltage
4 G Hazard lamp output Request to flash hazardsPulse must be >50ms
but less than 250ms
5 B/P Pinch strip ground — —
6 R Warning chime output Back door motor active Battery voltage
7 G/R Ignition switchIgnition switch ON Battery voltage
Ignition switch OFF 0
8 GR/B Back door close switchCLOSE position (ON) 0
NEUTRAL position (OFF) Battery voltage
9 L Warning chime ground — —
10 L/B Battery power supply — Battery voltage
11 YCinch latch motor
CLOSE outputBack door close operation Battery voltage
12 LClosure motor
RETURN outputBack door release operation Battery voltage
13 P/LBack door close switch
(While operating back door)CANCEL position (ON) 0
NEUTRAL position (OFF) 9
14 P Close switch signal While fully opening back door
15 O/L Open switch signal While fully closing back door
17 GR Glass hatch ajar signalGlass hatch OPEN 0
Glass hatch CLOSED 5
18 GR/R Park switchP or N position (Ignition is ON) 0
Other (Ignition is ON) 9
19 BR/B Pinch strip RHDetecting obstruction 0
Other 4
20 V/G Pinch strip LHDetecting obstruction 0
Other 4
PIIA3278E
W IIA1047E
PIIA2171E

BL-112
AUTOMATIC BACK DOOR SYSTEM
Revision: October 20052005 QX56
Terminals and Reference Value for BCMEIS0 08 R8
21 W/V Power window serial link —
22 BR Half switch signal Back door half latch position0
23 L/W Power liftgate switchON 0
OFF Battery voltage
26 VBack door outside handle sig-
nalBack door handle switch (at rest) Battery voltage
Back door handle switch (open) 0 Terminal Wire
ColorItem ConditionVoltage (V)
(Approx.)
PIIA2344E
PIIA2169E
Terminal Wire
ColorItem ConditionVoltage (V)
(Approx.)
10 G Hazard lamp flash inputBack door active 0
Other 5
22 W/V Bus —
42 GR Glass hatch ajar switch Open 0
Closed 5
43 R/BBack door latch (door ajar
switch)Open 0
Closed 5
67 B Ground — 0
70 W/B Battery power supply — Battery voltage
PIIA2344E

AUTOMATIC BACK DOOR SYSTEM
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Revision: October 20052005 QX56
Back Door Power Supply and Ground Circuit InspectionEIS008RC
1. BACK DOOR POWER SUPPLY CIRCUIT INSPECTION
1. Turn ignition switch OFF.
2. Disconnect back door control unit.
3. Check voltage between back door control unit connector B55
terminals 3, 10 and ground.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace harness.
2. BACK DOOR GROUND CIRCUIT INSPECTION
Check continuity between back door control unit connector B55 ter-
minal 1, 2 and ground.
OK or NG
OK >> Circuit is OK.
NG >> Repair or replace harness.
During auto closing operations, if obstruction is detected, the
door does not operate in reverse.Back door motor assembly —
During close or cinch operations, the door does not operate in
reverse if the back door handle is operated.Handle switch systemBL-125
When the keyfob is operated, the back door does not operate
automatically.Remote keyless entry system inspectionBL-44Power window serial linkBL-112
Pinch strip system inspectionBL-121
Auto closure does not operate.Half-latch switch systemBL-122Cinch latch motor systemBL-126
Handle switch systemBL-125
The back door does not open.
(Closure motor rotation is not reversed.)Open switch systemBL-123
Handle switch systemBL-125
Warning chime does not sound. Back door warning chime systemBL-122
Auto closure operation works, but the back door is not fully
closedClose switch systemBL-124Handle switch systemBL-125
Cinch latch motor systemBL-126
Back door latch assembly mechanism dam-
aged or worn.— Symptom Suspect systems Refer to
3 - Ground : Approx. battery voltage
10 - Ground : Approx. battery voltage
WIIA0567E
1 - Ground : Continuity should exist.
2 - Ground : Continuity should exist.
LIIA0801E

BL-116
AUTOMATIC BACK DOOR SYSTEM
Revision: October 20052005 QX56
Power Liftgate Switch System InspectionEIS008RD
1. POWER LIFTGATE SWITCH FUNCTION INSPECTION
Check power liftgate switch using switch operation.
OK or NG
OK >> Power liftgate switch is OK.
NG >> GO TO 2.
2. POWER LIFTGATE SWITCH POWER SUPPLY CIRCUIT INSPECTION
1. Turn ignition switch OFF.
2. Check voltage between power liftgate switch connector M92 ter-
minal 1 and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness.
3. POWER LIFTGATE SWITCH SIGNAL INSPECTION
1. Turn ignition switch OFF.
2. While operating the power liftgate switch, check voltage
between back door control unit connector B55 terminal 23 and
ground.
OK or NG
OK >> Switch is OK.
NG >> GO TO 4.
4. POWER LIFTGATE SWITCH CIRCUIT INSPECTION
1. Disconnect power liftgate switch and back door control unit connector.
2. Check continuity between power liftgate switch connector M92
terminal 1 and back door control unit connector B55 terminal 23.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness.1 - Ground :Approx. battery voltage
LIIA1551E
Te r m i n a l s
ConditionVoltage (V)
(Approx.)
(+) (-)
23 GroundPower liftgate
switchON 0
OFF Battery voltage
LIIA0802E
1 - 23 : Continuity should exist.
LIIA1064E